The present invention relates in general to a valve system for an internal combustion engine. More particularly, the present invention relates to a rotary valve system for an internal combustion engine.
The four cycle internal combustion engine presently in use incorporates the reciprocating poppet valve system for the transfer of air and fuel into the combustion chamber and exhaust gases from the combustion chamber. Most of these reciprocating systems involve complicated linkages, cams and springs. In many cases, the number of valve train parts exceeds one third the total number of parts comprising the entire engine. As a result there are horse power losses due to reciprocating inertial losses, cam shaft losses and losses due to valve spring compression.
In an effort to improve the valve system, rotary valves have found some limited use. The rotary valve system contains fewer and simpler parts which are more easy to produce. Due to non-reciprocating rotary motion, the principle retarding effects are frictional due to the sealing and bearing surfaces. Thus, the horse power losses with a rotary valve system are less than with a poppet valve system.
The prior art rotary valve systems are of generally two basic types; disc type or cylindrical type. These valve systems generally incorporate a valve drive shaft for each valve and the valves are lubricated by some external means such as by use of an oil or grease pump. Also, these systems usually incorporate slip rings to aid valve sealing. Alignment problems usually result when single shaft, multible cylinder, in-line rotary systems are used. The primary drawback to these rotary valve systems is that there is excessive use of the lubricating oil when the valve is lubricated properly. If the valve is not lubricated properly then scoring or seizing may occur due to friction and thermal effects.
One well known rotary valve system is referred to as the Aspin design which has met with some success. This design is of conical shape and is co-axially aligned with the cylinder. Also, this valve essentially forms a part of the combustion chamber. Again, one of the drawbacks with this arrangement is that it is difficult to maintain sufficient lubrication between the valve cone and the sealing surfaces without having a high consumption of the lubricating oil. Also, as far as modifying existing engines, it is more difficult when the valve itself forms a major part of the combustion chamber.
Accordingly, one object of the present invention is to provide an improved rotary valve system.
Another object of the present invention is to provide a rotary valve system incorporating a single support shaft for use with an in-line combustion engine.
A further object of the present invention is to provide a rotary valve system wherein the rotor is self-lubricating and self-fitting.
A further object of the present invention is to provide a rotary valve system that provides increased power, efficiency and response in comparison to known valve systems.
Another object of the present invention is to provide a rotary valve system for use with an internal combustion engine wherein the system can be possibly maintained and repaired without requiring removal of the entire head of the engine.
Still another object of the present invention is to provide a rotary valve system for an internal combustion engine that is quiet in operation, simple to design and manufacture, has fewer moving parts than existing systems, and that is less vibrational than existing systems.